I did a vacuum test. It looks like I have 19 lbs. of steady vacuum. When I rev up the engine it drops to about 4 then right back to 19 when I let off of the throttle. I would say it all looks good. I'll look at hose #7 and report back. (I've actually done a rear brake cylinder job in between checking these posts) BTW what is #7 hose suppose to control?

 

I vote to add it to the DIY section tool.

 

A few years ago, a friend bought an old Toyota Supra from a private party for $500.
It had a good straight body, straight 6 cyl/5 spd, but guzzled oil and smoked heavily. He tried all kinds of guesswork on it...No luck. I looked at the motor and saw a heavily crusty valve cover, especially at the PCV. I got him a Kragen $3.00 PCV for it and bingo...That took care of that problem. I think he gave it to his son for a drift car project.

 

Going from memory so don't quote me directly-too tired/lazy to pull out my manual right now...It ties into the vac secondary and the accel pump...trust me in a stick shift, you'd think the carb needed to be replaced, a DEAD spot under light accel at ~1800 rpm's. In the auto trans 3rd gen's I have found this to show up in a steady ~45mph drive, the engine seems to stumble lightly every few seconds or so-you chase a tune up, carb cleaner, fuel filters, ect..to find a little dang hose is burnt......I've had to replace this same hose on three of the four 3rd gen carb'd Accords I have owned in my life , they all showed the same signs...owned more 3rd gens but that is a story for another day.

 

I looked at hose #7 going into the back of the carb near the firewall. It was okay. As far as I could tell it was not burned nor cracked. This hose comes from the base of the carb to the vacuum rail and connects to one of the metal tubes. It goes to the plenum over on the passenger side and I'm not sure what it is tied to inside that box. I must admit the symptoms you described are nearly exactly what I'm experiencing except I noticed this week it happens at different speeds. Not just the @45mph I mentioned earlier.
I am now thinking towards some sort of gasoline problem. I know you mentioned chasing a tune up, carb cleaner, I even bought new fuel filters already and haven't put them in.
The reason I say this is because it is acting like a car does when it has water in the gas. You know how it will chug chug hit miss then all of a sudden purring like a kitten. Then back to the miss again. No certain place or specific speed like I described before. It's either got to be a loose wire that is missing a beat every now and then or a gasoline problem. Maybe I'll adjust the high speed screw. I may have it screwed in too much as I was trying to compensate for the high idle when the PCV valve was toast. I'll keep you all posted in days ahead. One more thing. I have a vent hose on the gas tank that I know is split. The reason I know is if I put more than 10 gals in the tank then it starts to run out of this hose. It's in a bad location just up above the back fuel filter and I will need to lower the tank but I'm sure it will be do-able.

 

The hose/rubber part I'm use to is only like 3 inches, maybe two...base of the carb to the top of the carb???? I'll see if I can get pic's from the 89 this weekend to be sure we are on the same page.

 

Yeah, I'm pretty sure I found the hose you were asking me to look at. It was just a couple of inches long, came out of the carb in the back but then hooked p to the metal vacuum lines that go to various locations. This one in particular goes back to the vacuum plenum box near the passenger's side of the engine compartment. Anyway it looks good with no cracks or burns. I've been babysitting and haven't had time to look at the other problem I mentioned. (the split hose near the gas tank)

 

ok, was just putting out an idea......rule out the maint stuff first.